chmod 431 Permission Explained

Notice: This is an unusual permission set: some classes have more access than the class above them. It is rarely correct in practice.

Octal

431

Symbolic

r---wx--x

Binary

100 011 001

Risk Level

Moderate

Summary: chmod 431 gives the owner read, the group write/execute, and everyone else execute.

Class	Read (4)	Write (2)	Execute (1)	Octal
Owner (u)				4
Group (g)				3
Others (o)				1

setuid (4) setgid (2) sticky bit (1)

Octal

Symbolic

Target File / Path

-R Recursive -v Verbose

431

r---wx--x

Owner: read · Group: write/execute · Others: execute

chmod 431 filename

Moderate Every member of the group can modify this file.

View the full chmod 431 guide →

chmod 431 Breakdown

Class	Digit	Symbolic	On a file	On a directory
Owner (u)	`4`	`r--`	Read only	Can list names, but not enter
Group (g)	`3`	`-wx`	Write and execute	Can enter and create/delete files, but not list
Others (o)	`1`	`--x`	Execute only	Can enter (cd) but not list contents

Is chmod 431 Safe?

Moderate

Every member of the group can modify this file.
Even the owner cannot modify this file without changing permissions first.
Unusual: a lower class has permissions the class above it lacks.

Common Use Cases

431 is uncommon in standard Linux setups. The closest widely used permission is chmod 400.

chmod 431 Command Examples

# Apply using octal mode
chmod 431 filename

# Apply using equivalent symbolic mode
chmod u=r,g=wx,o=x filename

# Recursive command warning:
chmod -R 431 /path/to/dir
# Note: -R applies the same mode to files and directories. Use find to treat them separately:
find /path/to/dir -type f -exec chmod 431 {} +

# Verify permissions
stat -c '%a %A %n' filename    # Linux
stat -f '%Lp %Sp %N' filename   # macOS

# Example ls -l output:
-r---wx--x 1 alice staff 1024 Jan 15 10:00 example.txt

umask Relationship

A umask of 346 makes new directories 431. Test umask values with our interactive Umask Calculator.

Frequently Asked Questions

What does chmod 431 mean?

chmod 431 gives the owner read, the group write/execute, and everyone else execute. In octal notation, the owner receives 4 (read), the group receives 3 (write/execute), and others receive 1 (execute).

Is chmod 431 safe?

chmod 431 is classified as Moderate. Every member of the group can modify this file.

What is chmod 431 in symbolic notation?

In symbolic notation, chmod 431 is represented as r---wx--x. You can apply this permission using the equivalent symbolic command "chmod u=r,g=wx,o=x filename".

Related Permissions

Change one bit:

chmod 031 remove owner read chmod 631 add owner write chmod 531 add owner execute chmod 471 add group read chmod 411 remove group write chmod 421 remove group execute chmod 435 add others read chmod 433 add others write chmod 430 remove others execute

← chmod 430 chmod 432 →

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